问题在下面备注部分

import java.awt.Container;
import java.awt.FlowLayout;

import javax.swing.JFrame;
import javax.swing.JLabel;

public class Ku extends JFrame {

    public Ku() {
            
        super("talk");
        Container c=this.getContentPane();
        c.setLayout(new FlowLayout());
        JLabel lbl=new JLabel("dialog");
        c.add(lbl);
        this.setSize(400, 500);
        this.setVisible(true);
        Ku k=new Ku(this,"对话框",false);/*这为什么会报错啊*/
        k.setSize(100, 100);
        k.setVisible(true);
        
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
    }
   
   
    public static void main(String[] args) {
        new Ku();
    }

}